Filtering device for lint and the like



May 31, 1960 Filed Jan. 7, 1959 O. BOLYA! FILTERING DEVICE FOR LINT AND THE LIKE 2 SheetsSheet l May 31, 1960 o. BOLYAI FILTERING DEVICE FOR LINT AND THE LIKE 2 Sheets-Sheet 2 Filed Jan. 7, 1959 United States Patent FILTERING DEVICE FOR LlNT AND THE LIKE Oscar Bolyai, Fall River, Mass., assignor to Hoyt Mfg. Corp., Westport, Mass, a corporation of Massachusetts Filed Jan. 7, 1959, Ser. No. 785,445

4 Claims. (Cl.183--52) This invention relates to filtering devices for the removal of solid particles from streaming gases, and more particularly it is concerned with a self-cleaning filter trap for lint and the like.

In automatic dryers for clothes, it is usually the practice to provide some form of filtering device to prevent lint and other small foreign particles from being exhausted from .the unit along with the drying air. Otherwise a nuisance is created by the lint that collects in the vicinity of the exhaust. Some units have very elaborate lint traps including a liquid medium to absorb suspended lint particles. Others simply incorporate some form of screen disposed in the path of the exhaust air. Most all have one thing in common, however, and that is the fact that after a time, often during a single drying cycle, they become loaded with lint and must be cleaned. This adds to the burden of laundering clothes and detracts appreciably from the attractiveness of an automatic clothes dryer as a time and labor saving mechanism. If the lint trap is not kept clean, the efiiciency of the dryer will usually be impaired because the flow of drying air is reduced.

It is a general object of the present invention, therefore, to provide a self-cleaning filter trap for lint and the like.

It is a more specific object to provide a filter trap of the above-mentioned character which is adapted to shake off accumulated lint automatically, at the end of each drying cycle.

Briefly, the objects of the present invention are accomplished by means of a frame defining an inverted receptacle disposed in the path of the exhaust stream, and a fabric covering over the frame. During the time that the dryer is operating, the body portion of the frame is constructed so that it will resiliently yield to the force of the stream of exhaust air, thereby permitting the covering to distort. However, as soon as the drying cycle terminates and the flow of drying air ceases, there is a recoil action of the frame, tightening the covering. In this way, accumulations of lint adhering to the covering are shaken off.

The novel features of the invention together with further objects and advantages thereof will become apparent when considered in connection with the following detailed description and the drawings to which it refers.

In the drawings:

Fig. 1 is a partial view of an automatic clothes dryer incorporating the filter trap according to the invention, certain parts of the dryer having been broken away to show the filter trap more clearly;

Fig. 2 is a perspective view of the filter trap according to the invention with a portion of the covering broken away to show the frame;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 1;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3, and

Figs. 5 and 6 are sectional views taken on line 5-5 of Fig. 1 showing the positions assumed by the parts when the dryer is operative (Fig. 5) and inoperative (Fig. 6). 1 7

With reference now to the drawings, and more particularly to Fig. 1, where there is shown an illustrative form of dryer unit embodying the invention, it will be observed that the numeral 11 represents one side wall of the unit, and the numerals 12 and 13 represent the walls of an exhaust duct through which drying air is passed out of the unit. An axial impeller 14 driven by a motor 15 serves to create the necessary flow of drying air.

The filter trap according to the invention is disposed across the mouth of the aforementioned duct and its construction is shown more in detail in Figs. 2 through 4. Thus the filter trap is seen to comprise a frame defining an inverted receptacle (inverted with respect to the direction of exhaust air flow) and a covering of fabric 21 over the frame. The character of the fabric will be determined largely by the nature of the particles to be filtered. For lint, woven textile fabric is suitable.

The frame itself is made up of four rails 2225 joined together to form the rectangular aperture of the receptacle and a pair of yoke-like members 27 and 28 extending between the rails 22, 24 adjacent their ends. As shown in Figs. 3 and 4, the rails have a channel shape when viewed in cross-section, one leg of the channel being joined to the edges of the exhaust duct walls which are flanged for the purpose. The other leg of the channel serves to retain the marginal edges of the fabric covering. To this end, the fabric is brought aroundthe edges and over the surfaces thereof, where it is held by means of clamping bars 29. The clamping bars are fastened by means of bolts 31 and nuts 32.

The yoke-like members 27 and 28 are round in section and have a sharp bend at each end. Rails 22 and 24 are bored in the vicinity of the corners of the frame in order to receive the ends. In this way, a pivotal connection is provided whereby the members 27 and 28 are permitted to swing toward and away from one another. Urging the members apart are springs 32 which, as shown, may take the form of simple leafs of resilient material fastened to the rails 22 and 24. There are also provided stops 33 which limit the extent to which these members can move toward one another.

In operation, the force of the stream of drying air impinging on the fabric and passing through the filter trap into the exhaust duct causes the members 27, 28 to move toward one another to the extent permitted by the stops. The direction of the exhaust air flow is as shown by the arrows in Fig. 5 where it will also be observed that with the members more closely together, the fabric is permitted to sag or distort. At the end of a drying cycle, however, when the flow of drying air is cut ofi, the members 27, 28 spring apart under the influence of the springs. This snaps the fabric taut and in so doing dislodges lint that has collected on'the surface of the fabric. If desired, a catch pan (not shown) may be positioned beneath the filter trap to catch the lint or other foreign matter having been dislodged.

Although the invention has been described in connection with a single preferred embodiment, those skilled in the art will appreciate that this embodiment is suscepti'ble of various modifications that are Within the spirit and scope of the invention. For example, the form of the frame and the type of the fabric may be altered considerably depending upon the particular application. Therefore, the invention should not be deemed to be limited to the details of what has been shown herein by way of example, but rather it should be deemed to be limited only by the scope of the appended claims.

' What is claimed is:"

'1. A filter trap for fine solids being carried in a gaseous stream, said filter trap comprising a rigid rectangular frame to define the mouth .of areceptacle disposed in V the pathjof th'e'strealm, rigid members pivo'tallvjoined to "said frame, said members defining thebody ofg t h'e receptacle, a fabric covering for the sides and bottom ofithejreceptacle', said covering being attached to said frame and defining 'a single opening interiorly thereof, andsprin'g biasing means rigidly attached to said frame for urging'said members apart, said biasing means being yieldablejtolthe force ofthe stream acting to move the members togetherlso thatwhen the stream terminates said'members recoil,tightening thejfabric and dislodging solids'therefrom.

2 A filter trap for fine solids being carried in a gaseous stream, said filter trap comprising a rigid rectangular frame to jd'efine the mouth of a receptacle disposed in theipath of the stream, a first U-shaped memher having itstermin'al ends pivotally joined to opposite sides of the frame, a second U-shaped member having its terminal ends pivotally joined to the same sides'of the frame as said first-named U-shaped member, said U-sh'aped members having pivot axes extending parallel and adjacent the other sides of said frame, a fabric covering for the 'sides and bottom of 'the receptacle, said covering being attached to said frame and defining a single opening interiorly thereof, and spring biasing means attached to said frame for urging said members apart, said biasing means being yieldable to the force of the stream acting to move the'members together so that when the stream terminates" said members recoil, tightening the fabric and dislodging solids therefrom 3. The combination according to claim 2 wherein said spring biasing meanscomprises a leaf spring acting'directly on each leg of said U-shaped members.

4. A filter trap according to claim 3 including means to limit the amount of swinging movement of said mem bers towards one another.

References Cited in the file of this patent UNITED STATES PATENTS V Zimmer r Mar. 2 1, 1916 1,324,635 Asc'oli Dec. 9, 1919 FOREIGN PATENTS 282,743 Great Britain May 17, 1928 

